Question

A bolt-nut connection with material quality 8.8 (h = 2mm, d1 = 13.54mm, d2 = 14.7mm) is tightened with a pre-blower blow dryer = 2500 daN. Safety coefficient S = 2.5, key length l = 10d, friction coefficient µo = m ’= 0.17; The average diameter of the contact surface with the nut is given as d0 = 1.4 d. According to the given

a) strength control calculation during tightening;

b) hand force to be applied to the wrench

c) After the operating force affects, find the characteristic of the bolt since Ftop = 3000 daN, since the total elongation of the bolt Dlctop = 0.04mm.

d) Since the elongation of the part when the pretension force is applied is =lp = 0.15mm, the characteristic of the part and the minimum shortening value remaining after the prestressing force is

e) Calculate the part of the operating force per bolt (Fic) and the part (Fip).

Answer 1

where, p = 25oodan lidanalon di = 13.54 mon d2.14.7 mm strength control calculation during tightening p de = Aly 2 I dit I 25000 N 25000 2 mm 7 x (1 3:54) 173:625 N/mm2 - Mt - 0-098p de 0.098x25000x 14.7 236015 N-mm I a 16x36015 3 [6Mt a di KX (13:54) 73.8920 195 W/mn? The principal Shear stress is given by Imax 012 f 2 2 173:6%)*4(73.87) 144.000624 vimine Y